<span>
    <span ng-if="running">
        <span class="fa fa-spinner fa-spin" ng-class="promiseButtonBusySpinnerClass"></span>
        <span ng-if="promiseButtonBusyText">{{promiseButtonBusyText}}</span>
        <span ng-if="!promiseButtonBusyText" ng-transclude></span>
    </span>
    <span ng-if="!running" ng-transclude></span>
</span>
